Various types of washing machines have been introduced to wash the interior surfaces of large tractor trailers and other vehicle bodies. Such washing machines vary. Some devices include a horizontal boom having washing heads on the free end thereof and moveable longitudinally into and out of a tractor trailer or other vehicle body, from one end thereof.
In another type washing machine, a mobile frame or wash cart is driven into the rear of the trailer from a support platform registered with the open end thereof. Such washers normally are coupled with flexible hoses which supply electric power, water and detergents from an external source to the mobile washing machine. In such devices, cable reels or spools are mounted on the mobile frame which hold the hose and effect hose takeup thereof as the mobile frame moves across the floor of the associated tractor trailer and wherein the cable reel is positively driven during reverse movement to take up the the hose as the machine reverses direction towards the open end of the vehicle body.
In particular, the applicants have developed a four-wheeled machine for the interior washing of a trailer body as set forth in their prior U.S. Pat. No. 4,309,788. The machine thereof sets on a base frame structure which supports the machine and which is provided with a drop gate at the front end thereof, to close the gap between the trailer and the base frame for the machine's entrance into the rear of the trailer. The base frame may be mounted on either a stationary dock for backup use, or on a laterally moving base for drive-by use. With a trailer positioned so that the interior washer is at the rear, open end of the trailer, operation is initiated by depressing a pushbutton control. The truck washing machine moves forward on its base allowing the drop gate to lower and to come to rest on the rear of the trailer for floor. The machine upon entering the rear of the trailer sprays soapy water on all four surfaces and scrubs the floor with rotary brushes. Detergents are injected into the water flow from a self-contained chemical tank within the four-wheeled machine frame or chassis. Washing of the interior with soapy water normally occurs during a first cycle movement from the rear of the vehicle towards the front of the trailer and reversely. Rinsing takes place during the return of the vehicle. In U.S. Pat. No. 4,309,788, as the machine exits from the trailer, it returns onto the base frame and automatically lifts the top gate as it approaches the rear of the base frame. Means are proved for automatically refilling the machine with water during the time when the trailer is pulled forwardly from the washing area and the next trailer to be washed is driven into position relative to the base frame. Such mobile, wheeled machines as known, are powered by either an electric or a hydraulic system, or a hybrid system. As a result, manufacture and maintenance costs are high, to ensure both the hydraulic and electrical system components are protected from the corrosive atmosphere on the wash cart. However, since the water, soap solutions and the like are extremely deleterious to the electrical and hydraulic controlled components, there are frequent break downs resulting in significant maintenance costs.
It is therefore a primary object of the present invention to provide a wheeled truck washing machine for the interior washing of a trailer body or the like, in which the water under pressure, supplied from a remote source to the mobile washing machine, provides exclusively, the requisite power to drive the machine into and out of the trailer body, the control fluid for reversing operation of the water powered equipment thereof, and the wash liquid, is unidirectionally supplied to the wheeled machine, requires no circulation loop and eliminates the need for electricity and/or hydraulic oil at the wheeled machine for control and function operation, thereby significantly reducing both manufacturing and maintenance costs.